Improvement in electro-plating and gilding cast-iron



iii-titled 'gtatw new new.

Letters Patent No. 90,894, dated June 1, 1869.

IMPROVEMENT ELECTRO-PLA'IING-AND GILDING- CAST-IRON.

- The Scheduleheferi'ed to in these LottersPatent and making part of the name.

To aZl'wlw mit may concern Be it known. that I, HIRAMVTUQKER', of Newton, in the county of Middlesex, and State of Massachusetts, have invented an Improvement in Electra-Gilding and Plating'of Cast-Iron; and I do hereby declare that the following, taken in connection with the drawings which accompany and foim part of this specification is a description ofmy"inventlonsuflicient to enable those skilled in the art to practise it.

My present improvement relates to coloring the surfaces of cast-iron articles,'in wholeor in part, in imitation of other metals, for the ornamentation thereof,,said other metals being applied by the electro-metallurgicp'rocess.

In making such application of electro deposited metals, it is impossible to produce a deposit which will be epduring, provided the deposited metal is unprotected, without making the deposit of such thickness as will make its application expensive, either in time or cost, or both; and the object-of my improvement is to provide a means for protecting on. articles of castiron, a very thin coat, or a mere blush of electrodeposited metal, sufiicient only to give to the cast-iron the color and appearance of the metal deposited thereon, so that the surfaces of the cast-iron may be inexpensively ornamented, or surfaced with a coating that shall practically haveflthe same value as a deposit thick enough in itself to be'proof against injury from-contact or from atmospheric influences.

My improvement consists in coating surfaces ofcastiron articles by first electro-depositing the metal which is to. be presented to the eye in the finished article,

either directly, on the cast-iron, or on a foil laid there-- on, or on a sub-coating of clectro-de'posited metal, the outer electro-denosit being only thick enough for a covering, giving the color and appearance of the metal which is electro-deposited, and then covering the outer electro-deposit with a varnish, preferably using a copalvarnish, or a varnish having an oil base;

In practising myinvention, I first smooth or polish, preferably by grinding, the parts of the cast-iron to be electro-coated. If a sub layer' of metal is used, it is applied to said surfaces, either as a foil or as an electro-deposit, on which the outside coating of metal is electro-deposited but usually the show-coat of metal is to be deposited directly on the smooth or polished surface of the cast-iron, and then the show-coating of deposited metal,--;in-either case, is to be varnished.

The varnish -when skilfully applied does not materially detract froth-the appearance of the show-coating, and 'afl'ords an impermeable transparent coating,- which acts as a perfect preservative or guard to the show-coat of deposited metal against oxidition or discoloratiom-either of the show-coating or of the metal base beneath.

Most commonly, gold will be the metal to be deposited to form the show-coating, but in some instances cheaper metals will be used, especially to form contrasts.

I claim the improvement in surfacing cast iron .articles, by show-coatingthem with athin electro-deposit, and varnishing the same, substantially as described.

Also, cast-iron articles, having a thin show-coat of deposited metal'protectedby varnish, substantially as described.

HIRAM TUCKER.

Witnesses FRANcxs GOULD,.

M. W. FROTHINGHAM. 

